Preparation of bismuth ferric oxide nanoparticles for the microwave-induced photo-degradation of organic pollutants in greywater

Abstract

This work demonstrates a thorough investigation into the synthesis and characterization of bismuth ferric oxide (BFO) photocatalyst for microwave-induced photodegradation of organic pollutants in greywater. Microwave (MW) irradiation was executed to enhance the generation of reactive oxygen species, contributing to the catalytic effectiveness of the synthesized photocatalyst. Through an efficient ultrasound-assisted synthesis process, perovskite BFO nanoparticles with a rhombohedral crystal structure and a crystallite size of around 15 nm were successfully manufactured. Comprehensive characterization employing various analytical techniques including X-ray diffraction (XRD), Energy Dispersive X-ray Analysis (EDAX), Fourier Transform Infrared and Raman Spectroscopy, UV–Visible Diffuse Reflectance Spectroscopy (UVDRS), photoluminescence spectroscopy, Scanning Electron Microscopy (SEM), and Brunauer-Emmett-Teller (BET) studies provided insights into the structural, elemental, spectral, optical, morphological, and surface area properties of the nanoparticles. The UV–vis spectroscopy and Tauc's plot were employed to elucidate the band structure of the photocatalyst, providing insights into its essential electronic properties for catalytic applications. With a narrow optical band gap of 2.13 eV, the synthesized photocatalyst demonstrated suitability for optical applications and exhibited substantial catalytic activity in the microwave-induced photocatalytic degradation of greywater. Remarkably, it achieved a 93.5% reduction in total organic carbon (TOC) within 180 min under moderate 50-W illumination. Refining process parameters through optimization studies notably augmented degradation efficiency. Scavenging investigations validated the efficient mineralization of total organic carbon content. Kinetic assessments provided mechanistic insights into improved catalytic activity of BFO, which was attributed to a changed band structure that allows for fast charge transfer across interfacial layers. Moreover, the stability and reusability of the BFO photocatalyst were assessed over five cycles, highlighting its potential practical application as an efficient and reusable photocatalyst for greywater treatment. These findings underscore the promising prospects of BFO in addressing environmental challenges and advancing sustainable wastewater treatment technologies.